If you’re struggling to remove stubborn yellow stains from your toilet seat, cleaning expert Jennifer Kropf has an unexpected solution: WD-40. Simply spray a few spritzes on the stains, let it sit for 8-10 minutes, and scrub away. The stains should surrender without much of a fight. WD-40 leaves behind a protective layer that makes it difficult for new stains to stick, so your toilet seat will stay clean for longer.